• Title/Summary/Keyword: Mass imbalance

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Comparative Analysis of the Local Economic Impact of University Student Startup in Korea and China (한중 대학생 창업의 지역경제효과에 대한 비교분석)

  • Jin-a Lim;Wang Xia
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.19 no.2
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    • pp.181-196
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    • 2024
  • This study examines the impact of university graduate Startup rates on economic growth in the regions where universities are located, using panel data from 35 universities in 17 regions in Korea and 21 universities in 13 cities in China over a six-year period from 2016 to 2021. In Korea, a total of 35 universities were selected as part of the Ministry of Education's "University-initiated Startup" policy, including Startup-oriented universities, leading universities in Startup education innovation, Startup education bases, and excellent universities in Startup education, while in China, 21 universities were selected as part of the pilot bases established as part of the "Mass Entrepreneurship, Mass Innovation" policy. To analyze the economic impact of the universities on the regions where they are located, we aimed to conduct an empirical analysis of the economic impact using economic indicators of the economic growth rate of the regions where they are located. The results of the empirical analysis show that the Startup rate of university graduates in Korea and China both have a positive impact on the regional economic growth rate, but the Startup rate of local university graduates in Korea has a greater impact on the regional economy than in China. Based on the findings that the number of entrepreneurs produced by universities has a positive impact on the economic growth of their regions, this study draws implications for the role of universities and regions in revitalizing local economies and the establishment of systems to resolve the imbalance between metropolitan and non-metropolitan areas.

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A Study on the Basic Pattern Drafting Method Development of Men's J$\breve{o}$-go-ri -Collar Construction (2)- (남자저고리 원형제도법 개발을 위한 연구(2) -깃구성을 중심으로-)

  • 정옥임
    • Journal of the Korean Home Economics Association
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    • v.37 no.7
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    • pp.17-27
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    • 1999
  • According to the design method for constructing the Korean Men's Jo-go-ri(the traditional Korean jacket)collar, there are differences in form after its completion. In the construction design of the midsection of the gusset as in that of the basic pattern Jo-go-ri, not only was the positioning of the two sides of the collar not smooth, but also, when the collar strip(Dongjung) was attached, there would be an imbalance on one side or the other so that it was difficult to achieve symmetry. Therefore in this project, by applying the pattern design of the gusset midsection to that of the collar midsection, not only did attaching the collar(Kit) and the collar strip create a visual effect by equalizing the lengths of the two sides, but the construction was also easy. This method of construction introduces the three-dimensional aspect of the human form in its conic, spherical and cylindrical aspects, so that, through schematizing the scientific character of Korea's clothing, its appropriateness is verified. As a matter of fact, since there is no standardization of pattern whether for educational use or for mass-produced clothing, so that even the patterns used in computer-assisted design are executed according to the designer's personal skill, the reality is that after completion of construction the quality has not been uniform. For this schematization, inverse calculation of measurements pertaining to the calculation formula and of teaching materials has been referenced. In particular, the partial regulation of the calculation formula pertaining to the basic pattern construction, the method of making the collar midsection, and the construction method of the extreme and mean ratio adjustment, can be adjusted for all measurements, thereby providing the establishment of a design criterion and the possibility of the standardization of construction methods. The production method for the basic pattern design is as follows: 1) The conic angle for the Jo-go-ri's girth, length end neck width is fixed at 70(72) degree. 2) The radius of the cone is sleeve length. 3) The bust girth calculation formula is B/4 + 2.5 cm. 4) The armhole formula is B/4 + 2.5cm. 5) The neck width formula is B/10. 6) The ratio of the collar junction{width of collar(Kit) + width of collar strip(Dongjung) to the gusset length is 5:8. 7) The length of the side seam is a length intersecting the armhole line and the conic radius of sleeve length, that is an arc that exceeds the length of the Jo-go-ri's midsection.

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Antioxidant action of soy isoflavones on oxidative stress and antioxidant enzyme activities in exercised rats

  • Yoon, Gun-Ae;Park, Sunmin
    • Nutrition Research and Practice
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    • v.8 no.6
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    • pp.618-624
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    • 2014
  • BACKGROUND/OBJECTIVES: Isoflavones are widely believed to be beneficial to human health, in relation to their antioxidant potentials. Exercise can cause an imbalance between reactive oxygen species (ROS) and antioxidants. This study was conducted in order to investigate the ability of isoflavones in amelioration of oxidative stress induced by exercise. MATERIALS/METHODS: Male Sprague-Dawley rats were assigned to one of four groups: isoflavone-free with no exercise (CON-sd), isoflavone-free with exercise (CON-ex), isoflavone-supplemented with no exercise (ISF-sd), and isoflavone-supplemented with exercise (ISF-ex). Animals exercised on the treadmill for 30 minutes per day, five days per week. TBARS as a marker of oxidative stress and antioxidant enzyme activity, including SOD, GSH-px, and catalase were determined in liver tissue. Serum lipid profile was also examined. RESULTS: A significant effect of isoflavone alone was observed on abdominal fat pad mass. ISF-ex had significantly less abdominal fat pad than CON-ex. Both exercise and isoflavone treatment had significant effects on lowering plasma triglyceride (TG), thus, the ISF-ex group had a significantly lower TG level than the CON-sd group, by 30.9%. However, no differences were observed in plasma cholesterol, HDL-C, and cholesterol/HDL-C ratio. Exercise, isoflavone, and exercise-isoflavone interaction effects were significant on thiobarbituric acid reactive substances (TBARS) (P = 0.001, 0.002, and 0.005, respectively). The CON-ex group showed a higher TBARS level than the other three groups. By contrast, in the ISF-ex group, TBARS was restored to the level of the ISF-sd or CON-sd group. Isoflavone had a significant effect on superoxide dismutase (SOD) (P = 0.022) and catalase activities (P = 0.049). Significantly higher SOD and catalase activities were observed in ISF-ex than CON-ex. SOD and catalase activities showed an inverse pattern of TBARS. Taken together, isoflavones increased the activities of SOD and catalase with concomitant decreases in TBARS, indicative of decreased oxidative stress. CONCLUSIONS: Isoflavone supplementation enhances antioxidant action with attenuation of exercise-induced oxidative stress, as measured by decreases in TBARS, and inhibits body fat accumulation and plasma TG increase. Antioxidative effects ascribed to isoflavones may be partially exerted via enhancement of antioxidant enzyme activities.

Bone Metabolism and Estrogenic Effect of Phytochemicals (골 대사 및 phytochemicals의 estrogen 효과)

  • Kim, Bokyung;Kim, Mihyang
    • Journal of Life Science
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    • v.28 no.7
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    • pp.874-883
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    • 2018
  • Osteoporosis is a disease that increases the risk of fracture by decreasing the mass and strength of bone. It is caused by imbalance of osteoclast bone formation and osteoclast bone resorption. Bone formation by osteoblast is activated via bone morphogenetic proteins and runt-related transcription factor 2. $Wnt/{\beta}-catenin$ signaling and bone resorption by osteoclast are initiated by the binding of receptor activator of nuclear $factor-{\kappa}B$ ligand and receptor activator of nuclear $factor-{\kappa}B$. Menopausal women are at risk for many diseases due to hormonal imbalances, and osteoporosis is the most common metabolic disorder in 30% of postmenopausal women. When estrogen is deficient, bone resorption of osteoclasts is promoted, and the risk of osteoporosis especially increases in postmenopausal women. Hormone replacement therapy has been widely used to relieve or treat the symptoms of menopausal syndrome. However, long-term administration of hormone therapy has been associated with a high risk of side effects, such as breast cancer, ovarian cancer, and uterine cancer. Recently, phytochemicals have been actively studied as a phytoestrogen, which has an estrogen-like activity to cope with symptoms of menopausal syndrome. Therefore, in this review, we investigated the differentiation mechanism of osteoblast and osteoclast and the role of estrogen and phytoestrogen in bone metabolism in relation to previous studies.

The Effects of Wearing Roller Shoes on Muscle Activity in The Lower Extremity During Walking (롤러신발과 일반신발의 착용 후 보행 시 하지근의 근전도 비교)

  • Chae, Woen-Sik;Lim, Young-Tae;Lee, Min-Hyung;Kim, Jung-Ja;Kim, Youn-Joung;Jang, Jae-Ik;Park, Woen-Kyoon;Jin, Jae-Hong
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.137-148
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    • 2006
  • The purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes. Twelve male middle school students (age: 15.0 yrs, height 173.7 cm, weight 587.7 N) who have no known musculoskeletal disorders were recruited as the subjects. Seven pairs of surface electrodes (QEMG8, Laxtha Korea, gain = 1,000, input impedance >$1012{\Omega}$, CMMR >100 dB) were attached to the right-hand side of the body to monitor the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and medial (GM) and lateral gastrocnemius (GL) while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and EMG recordings. EMG data were filtered using a 10 Hz to 350 Hz Butterworth band-passdigital filter and further normalized to the respective maximum voluntary isometric contraction EMG levels. For each trial being analyzed, five critical instants and four phases were identified from the recording. Averaged IEMG and peak IEMG were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). The VM, TA, BF, and GM activities during the initial double limb stance and the initial single limb stance reduced significantly when going from jogging shoe to roller shoe condition. The decrease in EMG levels in those muscles indicated that the subjects locked the ankle and knee joints in an awkward fashion to compensate for the imbalance. Muscle activity in the GM for the roller shoe condition was significantly greater than the corresponding value for the jogging shoe condition during the terminal double limb stance and the terminal single limb stance. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the GM activity for the roller shoe condition increased. It seems that there are differences in muscle activity between roller shoe and jogging shoe conditions. The differences in EMG pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine joint kinematics during walking with roller shoes.

Correlation Between Walking Speeds and Lower Extremities Joint Moment in Obese (비만인들의 보행속도와 하지관절모멘트에 대한 상관관계 분석)

  • Shin, Sung-Hyoo;Kim, Tae-Whan;Kwon, Moon-Seok
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.105-115
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    • 2006
  • The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.

A Study on the trabecular change of Femur according to $17{\beta}-Estradiol$ Dosage in Ovariectomized Rat (난소 절제된 백서에서 에스트로젠 투여용량에 따른 대퇴골주 변화에 대한 연구)

  • Kim, Seong-Joo;Kim, Kyung-Wook;Lee, Jae-Hoon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.22 no.2
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    • pp.155-163
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    • 2000
  • Osteoporosis is the consequence of an imbalance between osteoclastic and osteoblastic activity, coupled with an increased rate of bone turnover observed with menopause. Estrogen is generally considered to maintain bone mass through suppression of bone resorption. The purpose of this study was to evaluate the rat femoral trabecular change not only in the deficiency of estrogen but also in the administration of estrogen following ovariectomy(OVX). 30 female Sprague-Dawley rats were subjected to bilateral OVX or sham surgery(control). Groups of OVX were divided into 4 groups. The first group was injected daily with vehicle alone for 20 days after 20 weeks following OVX. The additional groups of OVX was injected daily with low, medium, or high doses of $17{\beta}-estradiol$(10, 25 or $50{\mu}g/kg$ BW, respectively). All rats were sacrified 23 weeks after OVX, and their femur were processed for H&E, MT stain and histomorphometry. The results were as follows; 1. In the histomorphometric analysis, the trabecular bone volume/tissue volume, trabecular thickness and trabecular seperation were respectively $31.2{\pm}8.3%$, $54.3{\pm}4.8{\mu}m$ and $280.7{\pm}16.4{\mu}m$ in vehicle treated OVX group and $48.6{\pm}7.3%$, $90.4{\pm}4.5{\mu}m$ and $126.3{\pm}5{\mu}m$ in sham operation group, and they showed statistical significance compare to control group. 2. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in low doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group. 3. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in medium doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group, but they didn't show statistical significance compare to low doses of $17{\beta}-estradiol$ injected group. 4. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $46.4{\pm}4.5%$, $154.4{\pm}13.2{\mu}m$ and $113.7{\pm}12.8{\mu}m$ in high doses of $17{\beta}-estradiol$ injected group and they also showed statistical significance compare to OVX group, but they didn't show statistical significance compare to other experimental groups. From the above results, metaphyseal bone formation was markedly reduced in OVX rate but treatment of OVX rats with $17{\beta}-estradiol$ resulted in normalization of femur trabecular bone volume. But they didn't show statistical significance the effect of bone formation according to the dose dependency.

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Current Medical Therapies for Osteoporosis and Its Alternative Treatments Using Natural Products (골다공증 치료법과 천연물을 이용한 대체요법)

  • Oh, Seunghoon;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.25 no.1
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    • pp.113-120
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    • 2015
  • Osteoporosis is a major bone disorder defined as having bone mineral density (BMD) of 2.5 standard deviations or more below the peak bone mass. Osteoporosis will increasingly be a major disorder that faces the aging mankind. It is the result of an imbalance in the bone remodeling system, where bone constantly undergoes a cycle of resorption by osteoclasts and formation by osteoblasts. Estrogen deficiency in women following menopause is identified as the predominant reason that causes disparity in this system. Current medical treatments for osteoporosis include hormone replacement therapy (HRT), biphosphonates, and teriparatide, but have various side effects that raise questions concerning their medical safety and practicality. Alternative treatments involving natural product sources are under study to find a safer therapy. Many natural sources including lactoferrin and isoflavones and numerous traditional herbal medicines exhibit anti-resorptive or anabolic effects on bone and thus show promises to provide therapeutic agents in treating osteoporosis. Unfortunately, the majority of natural product treatments are still in its preliminary stages to prove their efficacy even though the development pace of treatment for osteoporosis is astounding in the past few decades. Further progress in pre-clinical studies and the subsequent clinical studies will someday lead to a breakthrough that takes us another step forward in science.

Integrative Study on PPARGC1A: Hypothalamic Expression of Ppargc1a in ob/ob Mice and Association between PPARGC1A and Obesity in Korean Population

  • Hong, Mee-Suk;Kim, Hye-Kyung;Shin, Dong-Hoon;Song, Dae-Kyu;Ban, Ju Yeon;Kim, Bum Shik;Chung, Joo-Ho
    • Molecular & Cellular Toxicology
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    • v.4 no.4
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    • pp.318-322
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    • 2008
  • Obesity is an increasing worldwide health problem that is strongly related to the imbalance of food intake and energy metabolism. It was well-known that several substances in the hypothalamus regulate food intake and energy metabolism. We planned an integrative study to elucidate the mechanism of the development of obesity. Firstly, to find candidate genes with the marvelous effect, the different expression in the hypothalamus between ob/ob and 48-h fasting mice was investigated by using DNA microarray technology. As a result, we found 3 genes [peroxisome proliferator activated receptor, gamma, coactivator 1 alpha (Ppargc1a), calmodulin 1 (Calm1), and complexin 2 (Cplx2)] showing the different hypothalamic expression between ob/ob and 48-h fasting mice. Secondly, a genetic approach on PPARGC1A gene was performed, because PPARGC1A acts as a transcriptional coactivator and a metabolic regulator. Two hundred forty three obese female patients with body mass index (BMI)${\geq}$25 and 285 control female subjects with BMI 18 to<23 were recruited according to the Classification of Korean Society for the Study of Obesity. Among the coding single nucleotide polymorphisms (cSNPs) of PPARGC1A, 2 missense SNPs (rs8192678, Gly482Ser; rs3736265, Thr612Met) and 1 synonymous SNP (rs3755863, Thr528Thr) were selected, and analyzed by PCR-RFLP and pyrosequencing. For the analysis of genetic data, chi-square ($X^2$) test and EH program were used. The rs8192678 was significantly associated with obese women (P<0.0006; odds ratio, 1.5327; 95% confidence interval, 1.2006-1.9568). Haplotypes also showed significant association with obese women ($X^2$=33.28, P<0.0008). These results suggest that PPARGC1A might be related to the development of obesity.

The Effects of Wearing Roller Shoes on Ground Reaction Force Characteristics During Walking (롤러 신발과 조깅 슈즈 신발 착용 후 보행 시 지면반력의 형태 비교 분석)

  • Chae, Woen-Sik
    • Korean Journal of Applied Biomechanics
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    • v.16 no.1
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    • pp.101-108
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    • 2006
  • The purpose of this study was to compare GRF characteristics during walking wearing jogging and roller shoes. Twelve male middle school students (age: $15.0{\pm}0.0\;yrs$, height: $173.6{\pm}5.0\;cm$, weight: $587.6{\pm}89.3\;N$) who have no known musculoskeletal disorders were recruited as the subjects. Kinematic data from six S-VHS camcorders(Panasonic AG456, 60 fields/s) and GRF data from two force platform; (AMII OR6-5) were collected while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and GRF recordings. GRF data were filtered using a 20 Hz low pass Butterworth. digital filter and further normalized to the subject's body weight. For each trial being analyzed, five critical instants and four phases were identified from the recording. Temporal parameters, GRFs, displacement of center of pressure (DCP), and loading and decay rates were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p <.05). Vertical GRFs at heel contact increased and braking forces at the end of initial double limb stance reduced significantly when going from jogging shoe to roller shoe condition. Robbins and Waked (1997) reported that balance and vertical GRF are closely related It seems that the ankle and knee joints are locked in an awkward fashion at the heel contact to compensate for the imbalance. The DCP in the antero-posterior direction for the roller shoe condition was significantly less than the corresponding value for the jogging shoe condition. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the DCP for the roller shoe condition was restricted The results indicate that walking with roller shoes had little effect on temporal parameters, and loading and decay rates. It seems that there are differences in GRF characteristics between roller shoe and jogging shoe conditions. The differences in GRF pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine muscle activation patterns and joint kinematics during walking with roller shoes.